Question

I am trying to create a class to abstract my SQLite methods from my business logic etc. However, I can’t seem to ever access my database because it appears as if it is never being created. Please see the code below. I open the database at the specified path. Then I close it later on. After the close, I use the terminal to inspect my Documents directory (within the app). At this point there is no file where I specified it. Does it only create the file when I insert data to the database? Or am I not properly creating the database?

#import "SQLController.h"

@implementation SQLController
@synthesize database;

-(id)initWithDefaultDB {    
    return [self initWithDBPath:[self dbFilePath]];
}

-(id)initWithDBPath:(NSString *)dbPath {
    self = [super init];
    if(self) {
        sqlite3 *db;    
        const char *dbPathCString = [dbPath UTF8String];
        int result = sqlite3_open(dbPath, &db);
        if (result != SQLITE_OK) {
            NSString *errorTag = @"Failed to open database at ";
            NSString *errorMessage = [errorTag stringByAppendingString:dbPath];
            NSLog(errorMessage);
            sqlite3_close(db);
        } else {
            const char *createQuery = "CREATE TABLE IF NOT EXISTS items (title TEXT, details TEXT, category TEXT);";
            self.database = db;
            char *error;
            if (sqlite3_exec(self.database, createQuery, NULL, NULL, &error) != SQLITE_OK) {
                sqlite3_close(self.database);
                NSLog(@"Failed to create table");
                NSAssert(0,@"Error creating table: %s", error);
            }
        }
    }
    return self;
}

-(NSString *)dbFilePath {
    NSArray *paths = NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES);
    NSString *documentsDirectory = [paths objectAtIndex:0];
    return [documentsDirectory stringByAppendingPathComponent:@"testdb.sqlite"];
}


@end

Answer 1

Do you ever write to the DB before closing it? Sqlite is lazy – it doesn’t create the DB until first write.

Another thing to look at is your creating the C string (dbPathCString) but not passing it into open (you’re passing dbPath).

-(id)initWithDBPath:(NSString *)dbPath {
self = [super init];
if(self) {
    sqlite3 *db;    
    const char *dbPathCString = [dbPath UTF8String];
    int result = sqlite3_open(dbPath, &db);